The protein and nucleic acid and interactions involved in forming the transcribing ribonucleocapsid of vesicular stomatitis virus will be characterized. Solubilization and reassociation of the nucleocapsid protein with various RNAs will be attempted. Defective particles will be used to try to design an in vitro replication system. Further studies of the synthetic capabilities and composition of defective particles will be undertaken. Studies designed to determine how defective particles originate are also planned.